Researchers at the Korea Institute of Geoscience and Mineral Resources (KIGAM) have developed a flame plasma pyrolysis (FPP) process that converts wet spent coffee grounds into anthracite-grade biochar in just 90 seconds, eliminating the need for energy-intensive pre-drying. The process handles feedstocks with roughly 55% moisture content, using LPG and compressed air to generate plasma flames at 800-900 degrees Celsius. The resulting biochar has a heating value of 29.0 MJ/kg, comparable to anthracite coal, and a fixed carbon content increase from 15.6% to 46.2%. Sulfur compounds are completely removed, preventing SOx emissions during combustion. The technology is 40 to 240 times faster than hydrothermal carbonization and over 20 times faster than torrefaction. The compact, ultra-fast design makes it suitable for decentralized on-site waste-to-energy systems, potentially applicable to food waste, sewage sludge, and agricultural residues. This addresses the challenge of converting high-moisture organic waste into valuable energy resources while reducing greenhouse gas emissions from landfilling and incineration. The research was published in the Chemical Engineering Journal.
